CAMBRIDGE, MA - December 3, 2007 "“ Metabolix, Inc. (NASDAQ: MBLX), a bioscience company focused on developing clean, sustainable solutions for plastics, fuels, and chemicals, announced today that Target (NYSE: TGT) has introduced in all 1,600 stores gift cards made using Mirel(TM) biobased plastic in time for the holiday shopping season. In July, Target test marketed gift cards made using Mirel in 129 of its stores.

Mirel is a family of biobased, sustainable and biodegradable plastics that provides an excellent alternative to traditional, petroleum-based plastics. Mirel also biodegrades in a wide range of environments including soil, home compost, wetlands, rivers and oceans unlike traditional persistent plastics.

Current Mirel production is from a pre-commercial plant while the commercial plant is under construction. Because Mirel is made from corn and the commercial plant will utilize renewable energy in its production, the environmental benefits will be significant. Unlike conventional plastics, Mirel will have a "negative CO2 footprint." In a recently-announced cradle to factory gate life cycle assessment (LCA) for Mirel bioplastic resin, Dr. Bruce Dale, professor of Chemical Engineering at Michigan State University, determined that its production reduces the use of nonrenewable energy by more than 95% and provides a 200% reduction in greenhouse gases (GHG) compared to production of conventional petroleum-based plastics.

About Metabolix

Founded in 1992, Metabolix, Inc. is an innovation driven bioscience company focused on providing sustainable solutions for the world's needs for plastics, fuels and chemicals. The Company is taking a systems approach, from gene to end product, integrating sophisticated biotechnology with advanced industrial practice. Metabolix is now developing and commercializing Mirelâ„¢ bioplastics, a sustainable and biodegradable alternative to petroleum based plastics. Mirel is suitable for injection molding, extrusion coating, cast film and sheet, blown film and thermoforming. Metabolix is also developing a proprietary platform technology for co-producing plastics, biofuels and chemical products in biomass energy crops such as switchgrass.

Metabolix and Archer Daniels Midland Company (ADM) are commercializing Mirel through a joint venture called Telles. The first commercial scale Mirel production plant is being constructed adjacent to ADM's wet corn mill in Clinton, Iowa. The plant is expected to begin operations in late 2008 and is designed to produce up to 110 million pounds of Mirel annually. Mirel will reduce reliance on petroleum and decrease environmental impacts relative to conventional petroleum based plastics.

For more information, please visit www.metabolix.com. (MBLX-G)

Safe Harbor for Forward-Looking Statements

This press release contains forward-looking statements which are made pursuant to the safe harbor provisions of Section 27A of the Securities Act of 1933, as amended, and Section 21E of the Securities Exchange Act of 1934, as amended. The forward-looking statements in this release do not constitute guarantees of future performance. Investors are cautioned that statements in this press release which are not strictly historical statements, including, without limitation, statements regarding completion of construction and commencement of operation of the commercial manufacturing facility, the actual manufacturing capacity of that facility, and the sales potential of Mirel, constitute forward-looking statements. Such forward-looking statements are subject to a number of risks and uncertainties that could cause actual results to differ materially from those anticipated, including, without limitation, risks associated with: the Company's dependence on ADM for construction of the commercial manufacturing facility, ADM's ability to complete construction of that facility on time and on budget, market acceptance of Metabolix products, and other risks detailed in Metabolix's filings with the Securities and Exchange Commission, including Form 10-K for the year ended December 31, 2006. Metabolix assumes no obligation to update any forward-looking information contained in this press release or with respect to the announcements described herein.

Metabolix, Inc.

Metabolix, Inc.

About Metabolix Founded in 1992, Metabolix, Inc. is an innovation driven bioscience company focused on providing sustainable solutions for the world's needs for plastics, chemicals and energy. The Company is taking a systems approach, from gene to end product, integrating sophisticated biotechnology with advanced industrial practice. Metabolix is now developing and commercializing Mirel(TM) bioplastics, a sustainable and biodegradable alternative to petroleum-based plastics. Mirel is suitable for injection molding, extrusion coating, cast film and sheet, blown film and thermoforming. Metabolix is also developing a proprietary platform technology for co-producing plastics, chemicals and energy, from crops such as switchgrass, oilseeds and sugarcane. Metabolix and Archer Daniels Midland Company (ADM) are commercializing Mirel through a joint venture called Telles. The first commercial scale Mirel production plant is being constructed adjacent to ADM's wet corn mill in Clinton, Iowa. The plant is designed to produce up to 110 million pounds of Mirel annually. Mirel will reduce reliance on petroleum and decrease environmental impacts relative to conventional petroleum-based plastics. For more information, please visit www.metabolix.com. (MBLX-G) For the Metabolix press kit please visit http://www.metabolix.com/news/press.html.

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